Question: How do I safely remove USB hardware drives, when it says it's still in use?!

I have an external hard drive, a digital camera, an eMaticebook_reader, a few flash drives, and MicroSD chip adapters all hookedup to my Windows system via a USB connection. Each warns me not tounplug without using the shutdown icon on the taskbar. Sometimes I geta message, cannot shutdown because it is still in use. No, it isn't!Nothing is being transferred to or from it. Nothing is being read fromit. I've opened the Task Manager and there are no programs runningthat are using the external devices.

I know the warning is real to not unplug the device while it's inuse--as I have some devices that my computer can no longer recognizeafter unplugging them without the using the proper "Safely removehardware" procedure. I have a couple of MicroSD adapters and one 16GBflash drive that had to be thrown away because of this. My questionis: why won't it shut down, what's the cause of it being accessed whenI know it is not being used, and how do I safely remove hardware orforce it to shut down when the computer says the device is busy. All Iwant to do is to remove my external devices safely!

--Submitted by: Roderick D.

Here are some member answers to get you started, butplease read all the advice and suggestions that ourmembers have contributed to this question.

I think this happens to nearly everyone, and I've asked the same questions when it seems like nothing could be accessing the USB drive. Sometimes I wait a bit, but my sure method is to restart the computer. After clicking restart, the operating system will do it's thing by stopping all running processes. Pull the USB device out the moment the screen goes black. My computer will reboot in about 1.5 min., so it's probably quicker than waiting out the USB drive.

All the mass storage devices that are on your computer are controlled and buffered by the OS. Buffered access provides faster access, so that is the typical operation mode for mass storage. There are applications for mass storage devices where the devices are accessed unbuffered, but if it has a file system on it and you want decent speed, buffering by the OS is needed. Even if no user process or application is accessing the device, the OS can be carrying on asynchronous buffering operations (read-ahead, writing out large buffered blocks that need to be written because they are "dirty", etc.). So what you are doing is requesting that the OS sync down the device and not access it any more, like it would do for a shut down. If the OS is not accessing the device, and doesn't need to, then the "safe to disconnect" message will appear, and everything is fine. However, if the OS is doing something with the device, then you will not get this message, and yes, if you disconnect it despite that, you are very likely to have the data on the device be damaged, and to not be able to use it after that.

When you restart or shut down your system, the OS will unconditionally sync the device down in preparation for the OS being shut down. Just as it must be sync'ed down when you request removal, the OS must sync it down before the system can shut down, or the same damage may occur, which the OS will act to avoid (by syncing down the device to the point that it can be removed).

So it goes. While I'm not up on the internals of Windows specifically, all OS's must do this with removable read/write mass storage devices to increase operating speed. I believe that you can specify that the access to a removeable disk be unbuffered in Windows, but this will make your access slower, your backups and restores will slow down, etc. since you have to access the physical disk a lot more if you're not buffering in main memory. However, you will have less wait to remove the disk. If you're running full backups, chances are it takes less time to run the whole backup and then shut down the system if and when you have to for removing the disk, as opposed to having the whole backup run slowly. On the other hand, if you're just backing up a few isolated things, or using it as backup storage for music and photos that are accessed sporadically, then you might not care how long these accesses take.

I use an external USB hard drive for my backups. I get the "still in use" message if I haven't closed the window that displays the drive contents. As long as all windows for the drive are closed, I've had no problem.

This will frequently be the problem, but something else is also going on. I use two USB hard drives, both plugged in at the same time. Closing Explorer will always free up my 500GB, but almost never my 2TB - in fact I nearly always have to reboot to clear the larger drive, because it remains "in use" even with *all* windows closed other than the desktop. And there's nothing on the desktop requesting it.

Your 500Gb drive is probably formated using the FAT32 file system.Your 2Tb just can't use that file system and must use the NTFS file system.

When using FAT12 (floppy), FAT16 (small hard drive) or FAT32 (medium to large hard drive), there are no area in use unless you are actively accessing a file.

When using the NTFS file system, there are ALWAYS two (2) areas that are constantly "in use": The Master File Table and the transactional journal.

Now, mainly because of those, the NTFS file system is very robust and forgiving. You can safely disconnect your 2Tb drive as long as there is no user file been accessed, it will be similar to a power failure. And, even if you do deliberatly disconnect as a file is writen, the only damage may affect the file been writen, you won't have any lost cluster, lost file or other errors, just an incomplete file that IS tagged as such.

I have the same issue with a WD Paasport 500GB ext HD. So far i have just been giving up on waiting and disconnecting, with no ill effects, but tis discussion has me worried, so it could help to know about the formatting.....How can I tell if it is FAT32 or NTFS?

I dont understand this whole thread. Is anyone aware that there are Safely remove USB drive programs that sit on your bottom task bar and you jsut click on them nad the disconue access to the drive you choose and ttell you you can remove it now?Why wont that work?here is the download site for one... there are others...http://safelyremove.com/download.htm

I occasionally have the same issue, the safely remove hardware tells me "Oh no, Uncle Bill!",but find quite often I can go into my computer, and right click and hit the eject button. If that fails, then I do what rje49 recommends...restart. I work in photography, and have never lost a fileas a result. As to why...it's a computer.

I have this same problem sometimes. I have several USB hard drives & flash drives. Whenever I have this problem, I simply choose to restart my PC. As soon as it all goes dark, just before the restart happens, I can & do safely remove whichever HD or Flash Drive that's hanging up. I got tired of tryig to find what was going on, & restarting the PC is the best solution for me. it is annoyng I know, but it works quite well for me, & takes just a couple of min. I only have this problem at times. It does not matter which one does it, I can use it just a few min later with no problem.

Sometimes the program that was accessing the USB device needs to be closed. This can be done by right clicking the Taskbar and selecting the Task Manager and exiting the program via the Processes tab.

"I have a couple of MicroSD adapters and one 16GB flash drive that had to be thrown away because of this..."

You may at anytime remove a USB powered deviced without using the "Safely Remove Hardware" menu. However, to resume using it again on the same computer, you should first power down your computer and then unplug it for about 1 minute. This resets the capacitors on the motherboard.

I was experiencing the same problem until I realized that the backup software that came on a recent external hard drive application was doing real-time backups to the C: drive; then transferring the accumulated files to the external drive the next time it was plugged in. Now I know to completely exit that software first, then I experience no shut-down problems.

Hi Roderick,Sometimes Windows is still trying to Index what ever new you place / removed on the USB's or just updating the Index File. other possibilities are the release of the letter assigned to each USB so you get the message, if you were to open Windows Explorer and point to the Internal Drive such as C and wait about 15 seconds Prior to using the Taskbar Icon to Eject any USB, that would do it, but if not :Just Log Off your Profile, un-plug the USB's Connected and Log back on.It was suggested that you re-boot the pc and that is an idea as well. I found that is just faster to click on the icon on the Taskbar and if i get one of those messages which is not often with Win 7, then i just log off and Windows finishes writting / or the task in process at which point I remove the USB. I have never had a problem loosing information or not being able to read that USB after using this process.As far as having thrown them away, I think that was a bit too quick a reaction on your part - If you try re-formatting them and that did not helped, it could have been because the actual memory chips used on USB's and MicroSD Storage Cards could have worn out or corrupted. Next time try re-formatting them first, if it does not work on your PC/Laptop try a friend's - The memory on Small Storage devices is delicate and if you Read / Write a lot from them - they will eventually fail.Hope that helps.Geo

I got into the habit of updating my SD card while plugged into the computer - deleting pictures & videos when no longer needed on the card. After a while, the digital camera said the card was corrupted and I had to reformat it.

Since then, I've been maintaining the card while in the camera and have not had to reformat it since.

I know NOT to remove anything hooked up, with out clicking on the 'remove safely' icon. But when it's NOT there & I can't access the "Task Manager" to find it, then what do I do? Task Manager WON'T open. Yes, I've lost stuff too & don't want this happening AGAIN!

Open Device Manager and look for USB Root Hub listings. Click to open them until you find the drive where the particular device is plugged in. Stop it and you should get the appropriate message. Close dialogs and unplug. Sometimes the PC will offer this option on it's own. If I remember correctly that happens when you right click the Task Bar balloon. - or left on the line telling you not to unplug.

General tip. Never take fright through your hands. Think first. It takes one to see one.

Whenever I've been unable to remove a USB drive safely, I first check the task manager to make certain that I've got no background services running (backup/anti-virus) that might be (unknown to me) accessing the drive in question. Once, I've eliminated that possibility, I generally find that Windows Explorer itself has somehow "locked" the drive in question, and simply closing that window will "free" the USB drive so that it can be removed safely. I'm running Windows XP SP2.

If anything on the usb device is still being used by a program on your PC (or Mac) this will happen, even if you don't notice any activity on the drive. Sometimes it can be as innocent as a photo that is still open in Preview (on a Mac) even if it is parked in your dock or hidden under other windows.

The safest thing to do is restart. Sometimes something you aren't aware of will be running and you won't be able to quit or restart. You can try using the Force Quit method (Mac), and if all else fails... bail out by holding down the power button.

there are 2ways to do this safely, open "my computer" identify the USB drive right click ejectthe second is probably the best preferred way, in the system tray click the < to expand hidden icons, look for the USB icon click on it "safely remove hardware, " highlight the drive press "stop" a safe to remove" message will appear when it its safe to remove. you can remove it safely, if you don't do this is might cause a mounting issue the next time you try to. use it, you may not be able to reopen it, to fix that get a linux program booted, open the drive with linux, then dismount it in linux, I found that "fixes the problem for windows. when improperly removed it leaves files open, blocking access to it. Linux repairs the open file problem, when properly unmounted in Linux.the smallest fastest linux is "Puppy linux." a free down load, install on a CD boot from it. then open your USB drive. http://puppylinux.org/main/Overview%20and%20Getting%20Started.htmThomas Lake

One of three things is likely preventing you from removing the drive: First, is if you have a windows explorer windows open that is pointed to that drive and have its contents on the screen. Second, your antivirus is in the process of scanning the device or has left a file/folder locked as active. Close the windows explorer (not internet explorer) windows and wait a minute or so and try again. Third: you have a program installed like a photo transfer program that is locking up the drive. I have one that installs with my Olympus camera and one with my Lumix camera. Pain in the rear they are, really. Close the programs like that that are sitting in your taskbar. Worst case scenario, close all windows and wait a minute and see. Last resort: If you shutdown Windows, it should force whatever process is using it to complete and the system should shut down normally. If not, there is a remote chance that you have a virus that is cataloging the files on the thumbdrive so it can phone home to its master for identity theft reasons. Scan your computer with antivirus.

Also, regarding your thrown away thumbdrives: While unplugging a drive before using "remove safely" can corrupt the data, the thumbdrive itself is often just fine. You just can't access that data anymore. You can re-insert the thumbdrive and reformat it like any other disk by opening My Computer, right-clicking on that drive, and selecting "Format". Be warned, it will definitely toast any data you have on that drive, and if you accidentally do this to a hard drive, well, things won't be pretty. You may want to try a long format (uncheck quick format) even though it will minutely decrease the lifespan of the drive (most thumbdrives have a finite lifespan based on the number of writes to each cell). The reasoning for this is that if a particular cell of the memory on the thumbdrive was damaged by unplugging it, the long format should catch it. If you can right-click it because the drive doesn't show up in "My computer" anymore, you may have to try re-partitioning it through the Computer Management-->Disk Management control panel in Administrative Tools (or right click "computer" and select manage). If you are uncomfortable doing this, have a geek friend try. If the drive still is not accessible, then recycle it. It's actually illegal in many states to throw electronics away now as there is a fair amount of lead in the solder of electronics.

Most flash drives are automatically set to run without a read/write cache for "Quick Removal". At least according to Windows, you're supposed to be able to remove your USB device without using the "Safely Remove Hardware" feature unless you have changed the properties for your USB drive to turn on Read/Write caching for better performance. If you have, then you need to use the Safely Remove Hardware feature.

You can quickly view the properties of your devices in a number of ways depending on what OS you're using. This command can be created on your desktop to quickly assess the properties of your devices, and safely remove them if you desire:

Right-click the desktop and choose New > Shortcut. Use this for a target:

%windir%\System32\rundll32.exe shell32.dll,Control_RunDLL hotplug.dll

where %windir% is the drive where your system is located (Usually C:\windows) so the command would look like this on most systems:

In Windows 7, clicking on Start _>Devices and Printers will usually bring up any USB devices in use and allow you to eject them.

I think the obvious is obvious here. If you have any open documents that originated from your USB drive you need to save them. If you ran any commands from your USB drive that are still running, you should shut them down. You can use the EJECT command from the shortcut I provided above. If all of that still doesn't work and you want to be absolutely certain that you don't corrupt the FAT on your USB, you should do a SHUT DOWN. Then remove the device before restarting. Doing a Restart could still damage your USB in rare circumstances. (Don't flood me with answers about how it works for you, I said RARE CIRCUMSTANCES).

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